1. Field of the Invention
The present invention relates to an intermittent ozonizing apparatus, which can supply ozone by using a simple compact blower.
2. Description of the Prior Art
A large amount of coolant water is used in power plants and chemical industries. Slime troubles have been caused by microorganisms or algae in water for supply whereby a water-way is clogged or heat-exchange efficiency is lowered.
In order to prevent such troubles, it has been considered to apply water having high ozone concentration. In order to produce the water having high ozone concentration, it is effective to use an intermittent ozonizing apparatus which produces the water having high ozone concentration by storing ozone on an absorbent during a long time by using a compact ozonizer having a small capacity and desorbing the stored ozone from the absorbent for a short time instead of the use of an ozonizer having a large capacity in view of its equipment cost and operation cost.
Referring to FIG. 1, one embodiment of the conventional typical intermittent ozonizing apparatus will be illustrated.
FIG. 1(a) is a flow diagram of the conventional intermittent ozonizing apparatus; FIG. 1(b) is a vertical sectional view of an adsorption-desorption tower; and FIG. (1c) is a vertical sectional view of an ozonizer. In FIG. 1, the reference numeral (1) designates an ozonizer; (2) designates an adsorption-desorption tower which stores ozone by absorbing the ozone generated by the ozonizer; (3) designates a recycling blower for recycling oxygen gas discharged from the absorption-desorption tower to the ozonizer (1); (4) designates an oxygen supply source which feeds oxygen to the ozonizer (1); (5a)-(5c) respectively designate valves such as electromagnetic valves; valve (5b) in a first conduit, valve (5a) is in a second conduit (6) designates a tank for a brine which heats the adsorption-desorption tower; (7) designates a heater equipped in the brine tank; (8) designates a brine pump which feeds brine from the brine tank (6) to the adsorption-desorption tower (2); (9) designates a refrigerator for coolling the adsorption-desorption tower (2); (10) designates an ejector which sucks ozone from the adsorption-desorption tower (2); (11) designates an ejector pump which feeds water into the ejector; (12) designates a temperature indication regulator which detects the temperature in the brine tank (6); and (13) designates a relay which feeds or interrupts current to the heater (7) depending upon the indication of the temperature indication regulator.
The adsorption-desorption tower (2) has a jacket structure as shown in FIG. 1(b). In the inner cylinder (2a), an ozone-adsorbent (2b) is packed and a brine jacket (2d) is formed between the inner cylinder (2a) and the outer cylinder (2c) and a brine is filled in the jacket which is connected through a brine coil (2e) to the brine tank (6) and a vapor pipe (2f) wound on the inner cylinder (2a) is connected to the refrigerator (9). As the ozone-adsorbent (2b), silica gel is usually and as a brine, ethyleneglycol or an alcohol is usually used.
The ozonizer (1) usually has a structure for silent discharge in a gap between a high voltage electrode tube (1a) and an earth electrode tube (1b) and the reference (1c) designates a high voltage bushing; (1d) designates a high voltage fuse and (1e) designates an insulating block.
One recycling system is formed by the recycling blower (3), the ozonizer (1) and the adsorption-desorption tower (2) in the order.
The operation of the apparatus will be illustrated. The operation mainly includes an ozone-adsorbing operation and an ozone-desorbing operation.
The adsorbing operation will be illustrated. Oxygen is fed from the oxygen supply source into the recycling system at a constant pressure in the normal state. The pressure is usually kept at 1.0 kg/cm.sup.2 G. The electromagnetic valves (5a), (5b) are opened and the electromagnetic valve (5c) is closed. When oxygen is fed into the recycling system by the recycling blower (3), a part of oxygen is converted into ozonized oxygen by a silent discharge during passing oxygen through the discharge gap of the ozonizer (1) to produce ozonized oxygen. The ozonized oxygen is fed into the adsorption-desorption tower (2). The adsorbent in the adsorption-desorption tower (2) selectively adsorbs ozone and the residual oxygen is returned by passing through the electromagnetic valve (5a) to the ozonizer (1) by the recycling blower (3). Oxygen corresponding to the consumption of oxygen as ozone is additionally fed from the oxygen supply source (4). The ozone-adsorbent is cooled at -30.degree. C. or lower by the refrigerator because the adsorption ratio of ozone adsorbed on the adsorbent is highly depending upon the temperature. When the temperature is lower, the adsorption ratio of ozone is higher whereas when the temperature is higher, the adsorption ratio of ozone is lower. Therefore, in the desorption of ozone, the temperature of the adsorbent is raised.
When the adsorbent in the adsorption-desorption tower (2) adsorbs ozone at substantial ozone adsorption equilibrium, the adsorbing operation is changed to the desorbing operation.
In the desorbing operation, the ozonizer (1), the recycling blower (3) and the refrigerator are stopped and the electromagnetic valve (5a), (5b) are closed and the electromagnetic valve (5c) is opened.
The brine is fed from the brine tank (6) by the brine pump (8) so as to easily desorb ozone adsorbed on the adsorbent and the temperature of the adsorbent is raised by heating. The heater (7) heats the brine to control the temperature to a constant temperature by the temperture indication regulator (12). In the state, the ejector pump (11) is actuated to suck ozone from the adsorption-desorption tower (2) by the ejector (10) and the ozone is bubbled and dissolved in water in the ejector (10) and the resulting ozonized water is fed to a part for the application.
The pressure in the adsorption-desorption tower (2) is reduced to about -70 cmHg by the suction. After the desorbing operation, it is changed to the adsorbing operation and the operation is continuously repeated.
In the intermittent ozonizing apparatus, the ejector (11) is driven only for about 5 to 10 min. per day. The availability factor is low and the pump capacity is remarkably large. Therefore, the capacity of power receiving devices must be large and the initial cost is so high as to be unfavorable. Moreover, the water flow ejector is used and accordingly, the pressure in suction is limited to about -70 cmHg because of water partial pressure.